The invention relates to a method and an apparatus for processing a picture signal to obtain a picture signal having improved properties, such as being noninterlaced or having a doubled fine number, while still being interlaced.
EP-A 0 361 558 describes a method and an apparatus of this kind. Therein, a median is determined of signals from two adjacent lines in a given field of the picture signal and from one line of a field preceding the given field and lying vertically between the two adjacent lines in the given field. Preferably, a direction of a contour is determined also, to control the apparatus such that it supplies the median if the contour direction is substantially vertical, and that it supplies an average of the signals from the two adjacent lines otherwise. The supplied signal is multiplexed with the signals of the given field to obtain the non-interlaced picture signal or is processed with the signals of the given field to obtain a field of an interlaced picture signal having the doubled line number.